Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

Abstract

Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given.Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

Plasma electron temperature measurement by foil soft-X-Ray spectrometer installed on TUMAN-3M and Globus-M2 tokamaks

“…For example, it allows to study internal MHD-oscillations of plasma and to determine location of the surfaces with a rational value of the stability margin [1,2], to evaluate losses of electrons by using the electron-cyclotron emission ECE [3] and escaping electrons [4], ELM-events [5,6], to monitor L−H-transitions [7] and many more [8][9][10][11][12][13][14][15][16]. Such devices are widely used in the tokamaks JET [17], MAST [8], DIII-D [18], Asdex-Upgrade [19], PDX [20], NSTX [21][22][23], EAST [5], MST [24], TCV [25,26], COMPASS [27,28]. The measurement in X-ray devices is performed without interference into the process under study.…”

Измерение Электронной Температуры Плазмы Фольговым Рентгеновским Спектрометром, Установленным На Токамаках Туман-3м И Глобус-М2

“…Например, она позволяет исследовать внутренние МГД-колебания плазмы и определять расположение поверхностей с рациональным значением запаса устойчивости [1,2], оценивать потери электронов за счет электронно-циклотронной эмиссии ECE [3] и убегающих электронов [4], ELM-события [5,6], отслеживать L−Hпереходы [7] и многое другое [8][9][10][11][12][13][14][15][16]. Такие устройства широко применяются на токамаках JET [17], MAST [8], DIII-D [18], Asdex-Upgrade [19], PDX [20], NSTX [21][22][23], EAST [5], MST [24], TCV [25,26], COMPASS [27,28]. В рентгеновских устройствах измерение производится без вмешательства в ход изучаемого процесса.…”